Abstract: Conditioning of Geological Models to Engineering Data

ARAKTINGI, UDO, DAVE BROCK, DON VASCO, and AKHIL DATTA-GUPTA

The most neglected parameter in reservoir description, and probably the most important for reservoir development, is permeability. Most reservoir descriptions focus on porosity because of all the available information (seismic data, well logs). Permeability descriptions are neglected because of the paucity of pertinent data. Information regarding permeability comes from core data and transient pressure tests which are not available for every well in a reservoir. Thus, permeability models are usually generated by applying some type of transform to the porosity description. However, the most pertinent permeability data resides in fluid flow measurements such as production and injection curves in time and tracer tests, which are commonly available. Such data has been ignored because no clear methodology was available to integrate it with seismic data, well logs and geological interpretation. Fortunately, with recent advances in reservoir engineering, such a methodology can now be formulated. It combines a 3D streamline simulator with geophysical inverse theory and simulated annealing. The permeability field is continuously perturbed until fluid flow simulations through the permeability model honor the input flow data while still honoring the geological interpretation. This approach is made possible by the fact that the streamline simulator can provide fluid flow simulations up to 10000 times faster than standard finite difference simulators.

The impact of integrating fluid flow data, in addition to geological interpretation in the reservoir description is illustrated in a field case study. Results show that fluid flow data should be used towards generating reservoir descriptions that can be used for reservoir planning and development.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria